Answer
Case A(34°C): $\dot{Q}_e=16.9\ kJ/min$
Case B(20°C): $\dot{Q}_e=18.9\ kJ/min$
Work Step by Step
From tables A-4 to A-6:
Inlet ($x_1=1, T_1=34°C$): $h_1=268.61\ kJ/kg$
Outlet A($x_2=0, T_2=34°C$): $h_2=99.41\ kJ/kg$
Outlet B($x_2=0, T_2=\ kJ/min20°C$): $h_2=79.32\ kJ/kg$
From the energy balance:
$\dot{m}h_1=\dot{m}h_2+\dot{Q}_e$
Given $\dot{m}=0.1\ kg/min$
Case A(34°C): $\dot{Q}_e=16.9\ kJ/min$
Case B(20°C): $\dot{Q}_e=18.9\ kJ/min$
